An electric motor or generator typically includes a commutator and a brush in contact with the commutator for conducting electric current thereto. It is often necessary to analyze the commutating characteristics of a motor or generator. This might be done, for example, in order to determine if the brush is accurately positioned so as to be in contact with the rotating commutator at desired times, to determine if the motor or generator is operating in an efficient manner, etc.
A known method of determining DC neutral and other commutating characteristics of a machine, such as a motor or generator, employs a probe formed of an ordinary writing pencil having a portion of the wood material thereof removed, thereby exposing the lead. A strand of wire is wrapped about the pencil in such manner as to contact the lead. The other end of the wire is connected to a voltmeter. The probe is then run along the edge of the commutating brush in order to obtain voltage readings along the bush as the machine is brough up to load.
The difficulty with this "pencil neutral" method is that it is extremely dangerous and hazardous, requiring the operator to be inside the machine while it is operating under various loads. Additionally, once measurements are taken and recorded, it may be extremely difficult to ascertain the precise location at which each measurement was taken. The usefulness of data thus obtained is severaly limited when the data cannot be accurately related back to the machine.
Accordingly, it is an object of the present invention to provide both means and method for accurately determining commutating characteristics of a machine such as a motor or generator.
An object is to provide such means which will provide data in a manner such that the data may be accurately related to the apparatus from which it was obtained.
A further object is to provide a device and method for enabling safe and efficient analysis of commutator characteristics.
The invention provides a device which may be used to determine commutating characteristics of a machine with the machine in place, without the removal thereof to another location for testing.
The present invention further provides means and method for accurately positioning a brush with respect to a commutator.